Prior lubricating equipment has been developed for general use wherein a reservoir of lubricant is carried on a wheeled cart and is dispensed by a dispensing system having a pump and various pressure control valves such as shown in U.S. Pat. No. 2,141,022. This type of apparatus is filled through an open top and utilizes a follower plate for pressurizing the lubricant. While this type of portable equipment is suitable for general purposes, it is often not suitable for specialized uses requiring high maneuverability around closely spaced machinery and where cleanliness is required in manufacturing plants. While the lubricating apparatus of the present invention may be of general use as a lubricating apparatus, it has particular advantages for lubricating machinery in plants wherein the lubricating apparatus must be highly portable to maneuver in and around closely positioned machinery and must be completely self-contained to be transported large distances in the plant.
In many types of plants, a high degree of housekeeping and cleanliness is required, and the lubricating apparatus need be as clean as possible in its operation, particularly in avoiding any exterior residue of lubricant on the apparatus such as can occur during filling operations. For example, in lubricating textile and food preparation machinery, contact of the fabric or food with the lubricant must be prevented. It is also a common problem that the environment of many types of plants contains dust, trash or wood chips and the like which can contaminate the lubricant if allowed to contact it during filling operations. Once the contaminants are in the lubricant, fouling of the dispensing system and/or the fittings being lubricated can occur.
Safety in refilling operations has also been a problem with prior devices, especially with the type which employ a pressurized container with a pressure-cooker type lid and lock arrangement wherein the container interior space is pressurized directly with air. An unskilled worker unfamiliar with such apparatus can quite easily injure himself by unlocking the lid before relieving the pressure resulting in the lid flying off under pressure.